1. Field of the Invention
The present invention is broadly concerned with humidification devices for creating contact between an incoming gas stream and a supply of water to produce a humidified gas output. More particularly, the invention pertains to such humidification devices, especially in combination with an overall gas delivery assembly such as a CPAP (continuous positive airway pressure) unit, wherein the humidifier includes a slidable drawer member allowing easy access for filling and cleanup of the humidifier.
2. Description of the Prior Art
Sleep Apnea Syndrome is a disorder characterized by cessation of breathing and frequent awakenings during sleep. One class of sleep apnea is obstructive sleep apnea, which is characterized by the obstruction of the person""s upper airway resulting in interference with breathing during sleep. In order to treat obstructive sleep apnea, CPAP devices have been developed to deliver air under constant positive pressure to the nasal passages during sleep. These devices are frequently successful in treating sleep deprivation due to obstructive sleep apnea.
In order to prevent drying of the breathing passages during the administration of CPAP, it is desirable to humidify the air supplied to the person using such devices. This may be accomplished by providing a humidifier which is essentially a bottle containing a quantity of water over which the air under pressure passes before being delivered to the user. The user partially fills the bottle with water, and the air is circulated within the bottle to pass over the surface of the water and absorb moisture therefrom.
U.S. Pat. No. 5,231,979 describes a CPAP humidifier in the form of an essentially completely enclosed body having tubular air input and output elements adjacent the forward end of the body. In order to fill the humidifier body, it is necessary to carefully pour water through one of the tubular ports until the water reaches a predetermined level. This can be troublesome and lead to water spillage. In addition, it can be difficult to clean such an enclosed humidifier body, particularly after a period of heavy use.
The present invention overcomes the problems outlined above and provides an improved humidifier for creating contact between an incoming gas stream and a supply of water so as to yield a humidified gas output stream. The humidifier is especially designed for use in conjunction with CPAP units, but may also be used with virtually any type of breathing device where humidification is desirable, e.g., ventilators.
Broadly speaking, the humidifier of the invention includes first and second slidingly interfitted members, with the second member preferably being somewhat drawer-like and adapted to hold a supply of water. The members are relatively shiftable between an open position permitting filling of the second member with water and a closed, humidifying position wherein the members cooperatively define a air-water plenum chamber. A gas input and a gas output are in communication with the plenum chamber so as to direct gas into, through and out of the plenum chamber for humidification thereof.
In preferred forms, the first member is in the form of a stationary cabinet whereas the second member comprises an open-top, water-holding drawer member. A connection assembly including mating components on the cabinet and drawer member respectively is provided for slidingly supporting the drawer member within the cabinet and permits sliding movement of the drawer member between its open and closed positions. Advantageously, the connection assembly includes a slide track supported on the cabinet whereas the drawer member has a slider which is received within the cabinet slide track. Certain embodiments of the present invention include a projection in the cabinet located at the end of the slide track. This projection mates with a recessed region of the drawer member and operates as an abuttment against which the drawer contacts when inserted into the cabinet, thereby limiting further insertion of the drawer once the drawer is properly inserted into the cabinet. Other embodiments utilize a beveled drawer which is slidingly received by a cooperatively beveled cabinet. In this embodiment, the beveled drawer permits drawer insertion into the cabinet without interference from the sliding track. When the drawer is fully inserted into the cabinet, the beveled portions of the drawer engage the cooperatively beveled portions of the cabinet, thereby limiting further insertion of the drawer.
In alternate embodiments, the drawer member includes one or more resistance heaters for heating water contained therein. In this embodiment, mating electrical connectors are located on the cabinet and drawer so that, when the drawer is fully inserted within the cabinet, the connectors mate to complete a heating circuit.
The gas delivery devices (e.g., CPAP units) of the invention are designed to generate and receive patient gas and to convey such gas along a path of travel for ultimate delivery to the patient. The humidifier of the invention is designed with its gas input and output for coupling into the path of travel of gas.